Semax is a seven-residue peptide made from residues 4 to 7 of ACTH, the pituitary stress hormone, with the same Pro-Gly-Pro tail used in Selank. It was first described in the scientific literature in 1991.1
It is a prescription drug in Russia and on the Russian government's list of vital and essential medicines. It has not been evaluated or approved in the UK, the EU or the US.2
7
813.9 g/mol
1991
Russia only
Identity
Fig. 1 · Sequence map. ACTH positions 4–7, then the added Pro-Gly-Pro tail, shaded.
| Value | |
|---|---|
| Developer | Institute of Molecular Genetics, Russian Academy of Sciences |
| Based on | ACTH (4–7) plus Pro-Gly-Pro |
| Formula | C37H51N9O10S |
| Avg mass | 813.9 g/mol |
| CAS | 80714-61-0 |
History
What the studies measured
| Area | Model | What was measured | Source |
|---|---|---|---|
| Stability | Rat blood enzymes | How fast the peptide is broken down | [1] |
| Enzymes | Human serum in vitro | Inhibition of enkephalin-degrading enzymes | [3] |
| Brain chemistry | Rats | BDNF and TrkB in the hippocampus | [4] |
| Receptors | Review of binding data | Melanocortin receptor antagonism | [5] |
| Neurotransmitters | Rats and mice | Dopamine and serotonin systems | [6] |
Regulatory and sport status
| Where | Status |
|---|---|
| Russia | Prescription medicine; on the list of vital and essential drugs since 2011.2 |
| UK, EU, US | Not evaluated or approved. Not a controlled drug in the UK. May not be supplied or promoted for human use. |
| Sport | Not named on the WADA list. Because it has approval in Russia, class S0 may not apply; athletes should check with their anti-doping body.7 |
Open questions
- Clinical evidence that meets Western standards. The Russian clinical claims rest on older, smaller studies.
- Mechanism. Enzyme inhibition, BDNF and melanocortin receptor effects have all been proposed.
- Independent replication outside Russian institutes.
Common questions
What is Semax?
A seven-residue peptide made from part of ACTH, a pituitary hormone, with a Pro-Gly-Pro tail added for stability.
Is Semax approved anywhere?
In Russia, where it is a prescription drug. Not in the UK, the EU or the US.
How is it related to Selank?
Same institute, same Pro-Gly-Pro tail. Selank is built on tuftsin instead of ACTH.
Is Semax banned in sport?
It is not named on the WADA list. Athletes should check with their anti-doping body.
Does Semax act like ACTH?
The fragment it uses does not include the part of ACTH that drives cortisol release, and it is not reported to raise cortisol.
See also
References
- Potaman VN, et al. [First description of Semax and its degradation by rat blood enzymes]. Biochem Biophys Res Commun. 1991;176(2):741–746. PMID 1851003
- Wikipedia. Semax, citing the Russian List of Vital and Essential Drugs (7 December 2011), checked 2 Nov 2026.
- Kost NV, et al. Semax and selank inhibit the enkephalin-degrading enzymes from human serum. Bioorg Khim. 2001;27(3):180–183. PMID 11443939
- Dolotov OV, et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54–60. PMID 16996037
- Bertolini A, et al. [Semax as a melanocortin receptor antagonist]. Eur J Pharmacol. 2012;679(1–3):1–8. PMID 22293371
- Eremin KO, et al. Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents. Neurochem Res. 2005;30(12):1493–1500. PMID 16362768
- World Anti-Doping Agency. The 2026 Prohibited List. wada-ama.org
Peptidarium Library. Semax (entry 0012), revision 1.0, 2 November 2026. peptidarium.com/library/semax
Revision history
| Rev | Date | Change | By |
|---|---|---|---|
| 1.0 | 2 Nov 2026 | Entry created. | [Scientific editor] |
Spotted an error or a missing paper? Send a correction. Every change is logged here.